Two-stroke explosion engine



]. DE COSMO.

TWO-STROKE EXPLOSION ENGINE.

APPLICATION FILED M R. l9, 1917-.

1,41 3,974, Patented Apr. 25, 1922,

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2 I \f 3 f6 4 J. DE COSMO. TWO-STROKE EXPLOSION ENGINE. APPLICATIONFILED MAR. 19. 1917.

1,41 3,974. Patented Apr. 25, 1922.

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' r 4 I I I u n 1 u n n I I I I I INVENTOR JOSEPH DE Cosmo ATTORNEY JOSEPH DE COSIVIO, OF:LIEGE,,BELGI U1VL 'rwo-srnoxn nxrnosioit ENGINE.-

1 413 974. Specification of Letters Patent.

Application filed March 19, 1917. Serial No. 155,912;

(GRANTED UNDER THE Prhov'IsioNs-or runner or mac 3, 1921], 41 'sriir. n, 1313.)

To (ZZZ whomz't may concern:

Be it known that L JOSIPH=lHJ (Jos una subject of the King of Italy, residing in Liege, Belgium, have invented certain new and useful Improvements in Two-Stroke Explosion Engines; and I'do hereby declare the following to be a full, clear, and exact description ofthe invention, such as w ll on able others skilled'in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, a nd to letters or figures of reference marked therein, which Form a part of this sg'ie'ciiication. 1 I

The invention relates to a two-stroke explosion engine of the type wherein the driving piston has a sleeve-like extens on or l1ner in which moves a special scavenging piston,

that is a piston chiefly designed to expulse.

the burnt gases. The drawing annexed to the present specification illustrates by way oi example a iorm of a two-stroke engine or motor with .i'our cylinders constructed accordingto the above indicated principle,'thecranks being seciu'ed at90 Figure 1 shows the engine in'section' on the line C D of Figure 2 and shows the scavenging piston at the middle of the exhaust. 5

Figure 2 is a section on AB of Figure 1.

Figures 3 to 7 are axial cross-sections illustrating different forms of the scavengin piston according to my invention.

ln the cylinder 1, provided with openings for admission 2 and exhaust 3, moves a piston 4, receiving a reciprocating movement from the connecting rod 5wliich is connected ranged horizontally as shown on a larger scale in Fig. 0. V

The drive'of the scavenging piston is pen formed as follows: the sheaves or flanges of the crank shaft 6 are provided with cam surfaces 13 and 14, one of which acts upon 7 the roller 15 for the ascent of the scavenging piston, and the other upon the roller 16 for the descent of the scavenging-piston. To this end these rollers-1'5 and 16 are supported lVhile expelling'the burnt Patented Apr, 25, 1922. i

by arms 17 and 18 mounted upon an axle 19 it arrives at its lower dead-center, begins to uncover the exhaust openings 3 of cylinder.

1 by means or" the ports ,9, of its liner 7. The exhaust of the burnt gases begins and is soon hastened by theascent oi the scav nging pis ton 10, under the action of the contact of the cam 13 withroller 15. As the profile'of cam 1.3 is so calculated that the scavenging piston comes at stroke-end up to l min. of the to becomplete; t

On the other hand, the movement of the scavenging piston takes place smoothly and without shock, owing to theiact that one half of stroke is accomplished in a uniformly accelerated movement, and the other half in' aiiniforinly retarded movement. Further the pressure of burnt gases upon the scavenging piston during its'ascent isas itwere null, as the exhaust openings 3 are wide open before the scavenging piston begins to rise. i

On its downward movement moreover the driving piston 4i placed its ports 8 opposite to admission openings 2 of the cylinder, but the ports8 remained covered by the scavenging piston 10, until the latter began to rise; I gases, as just pointed-out, the scavenging piston 10 has uncovered-the ports -8, thus allowing fresh gas to rush into the space between the two pistons, Ara given time the drivingpis'ton,

' on its upv'r'ardstroke, covers again the exhaust openingsof' the cylinder and closes completely the admission of fresh gases;v which are" thus kept or coniined'between the walls of the liner, the bottom of the scaven ing piston, which has arrived at its upper stroke-end, andthe upperface of the driving piston. Then the cam 14 begins to thrust upon the roller 16 andthe scavenging piston at a given moment, a little" before I head, the exhaust'oi burnt gases may be consldered eli'ect of the pressure of the gases which ar compressed. by the two pistons moving in opposite directions, the valves 12 open automatically and make 'v vay'i or the gases {lon ing to the explosion chamber.

On continuing their stroke the driving and scavenging pistons ivill'meet each other, but this meeting tallies place Without shock, first because the profile of the cam 1.4-, like that cam 13, is so calculated that the downward movenrent of the scavenging piston be first accelerated and then retarted, and also because a little before the pistons meet each other the cam l3 acts again upon the roller and the pi, n 10' rises again at a, lower than the driving piston. Thus this meeting, that causes the closing of the valves 12, takes place While both pistons move in the same direction; both acting as a single piston, compress the gases While risin These gases are then normally ignited by the spark plug 23, when the driving piston has arrivedat its upper dead center. i i lien the explosion has taken place, both pistons are driven downward, the scax illglllj' piston bearing on the driving piston, until the scavenging piston alone rises again to ex Jel the burnt ases and to draw in the fresh gases, as explained just above.

Fi ure 3 shows a modification in which the valve 24-, which performs the same function as the checlovalves 12, is adapted to be operated concurrently with the scavenging piston 10. To this end the valve 2% is secured to rod 250 slidabiy mounted in the rod. ll of the scavenging piston. Opposite the slot in rod 11 is slot 31 in red 30, through which the lever is adapted to extend when in err-- gagement With slot 21, the relative arrangement of lever 20 and rod 11 being the same as in Fig. 1. Slot 31, however, is shorter than slot 2i, so that when the lever 20 moves upwardly its action is first to lift the valve 2st until it engages its seat and prevents the passage oi fluid through the piston l0.'

hen the scavenging piston again moves downwardly and the exhaust and admission have taken place, the valve 241 uncovers the ports in the scavenging piston and both the valve 241 and piston 10 continue their downward movement until piston 10 comes to rest on the Working piston. Compression then takes place as described with reference to Figs 1 and 2. e

I have already pointed out the numerous advantages procured by this engine with respect to dynamics, but its superiority is also established in regard to mechanics. 'lhe auxiliary shafts, cam shafts-and crank n to meet the drivingpiston. Under s alts driving the distribution pieces and their pinions have been dispensed'viith. irloreover, the distribution being controlled solely by the two pistons, the suction and ex iaust oipes as Well as the inlet and outlet tor water may be cast in one piece With the cylinder, so that the structure combines a great strength With a neat appearance While a great power or efliciency is secured tor small space occupied.

il laving thus described the invention, what I claim is: p

In a two-stroke explosion engine, the combination with a cylinder provided With inlet openings at th lower part and With exhaust openings at the upper part, of a driving piston, a liner carried by said driving piston, said liner being also provided with inlet and exhaust openings, a scaveng ing piston moving Within the drivingpiston,

a valve controlling an opening n said ivenging piston, arod for said scavenging piston entendnig through the driv ng piston and gulded by the latter, said rod being pro vided With a recess, lever extending into that recess, a pair of rollers carried by said lever, a crank shaft, and cam surlar s on the sheaves of said crank-shaft adapted to act upon said rollers to control the ascent and the descent of the scavenging piston. v

2. In a two-stroke explosion engine, the combination witha cylinder provided with inlet openings at the lower part and with exhaust openings at the upper-part, of dr'i ting piston, a liner carried by said driving pistoi'i, said liner being also provided 'with inlet and exhaust openings a scavenging piston moving Within the driving piston, a V valve cont-rolling an opening lnsaid scavenging piston, a r d tor scavenging piston extending through the driving piston and jgzuided by the latter, said rod being pro vided with a recess, a lever extending into that recess, a pair of rollers carried by said lever, a crank shaft, and cam surfaces on the sheaves of the said crank-shaft adapted to act upon said rollers to control the ascent and the descent of the scavenging piston, said cams having such a profile that the meeting of the driving piston and the scavenging piston occurs always when both the pistons are moving in the same direction. In testimony that I claim the foregoing as my invention, l have signed my name in presence of two subscribing witnesses.

' Witnesses:

R. HinNoAn'rNun, E. DESSIEOUR. 

